Several clinical studies have shown the emergence of immune checkpoint inhibitors (ICIs) could break the standard of care and generate clinical benefits for Extensive-Stage Small-Cell Lung Cancer (ES-SCLC). We aim to assess the efficacy and safety of immuno-based therapy in patients with ES-SCLC.
Our search was performed in PubMed, Embase, Cochrane, and Web of Science databases for clinical studies published in English between Jan 1, 2000, and Nov 30, 2021. We extracted hazard ratios (HRs) and 95% confidence intervals (CI) of overall survival (OS) and progression-free survival (PFS), objective response rate (ORR), grade 3 or higher treatment-related adverse events (AEs), and we calculated the 95% CI together with the incidence. In addition, subgroup analysis was performed for patients with brain metastasis, smoking, and liver metastasis.
We identified 200 records, of which 6 studies (2,905 patients) were included. The combined results showed that immuno-based therapy significantly prolonged OS (HR,0.78; 95%CI, 0.71 to 0.86; p < 0.00001), PFS (HR, 0.81,95%CI, 0.75 to 0.87; p < 0.00001) and ORR (HR, 1.06; 95%CI, 1.00 to 1.11; p = 0.03). Serious AEs (≥ 3 grade) were more frequent with immuno-based therapy Risk Ratio (RR), 1.08; 95%CI, 1.02 to 1.14; p = 0.007. Besides, the most common serious AEs were neutropenia (25.1%; 95%CI, 18.9% to 32.6%), anemia (12.2%; 95%CI,9.6% to 15.4%) and thrombocytopenia (8.3%; 95%CI 5.7% to 11.9%). Compared with standard of care, no obvious immuno-based therapy benefit was found for ES-SCLC patients with brain metastases at diagnosis (HR, 1.14; 0.87 to 1.46; p = 0.32) and smoking (HR, 0.88, 95%CI, 0.73 to 1.06; p = 0.19).
Our study reveals that immuno-based therapy better improves the OS and PFS than standard chemotherapy in ES-SCLC patients. Hence, our results provide new insights into the efficacy and safety of ICIs combination strategies for guiding clinical practice.